This question will probably bring out a few creationists! But here's my take.
Evolution may be important to us in a few ways. First, it needn't take quite as long as you state in your question. Modern humans, for instance, are less than a million years old as a species (according to most anthropologists). But even slow evolution may be important to understand in that it can give context to the present.
So, for example, if we consider the evolutionary effects of conflict between small groups, we may be led to consider the (disproportionately masculine) propensity to violence in a particular way--one that is different than if we consider that propensity to be purely a cultural thing.
Second, evolution--in the sense of adaptation within a species--can occur much more rapidly. The classic example is the English moth that was observed to change from a light coloration to a dark one for better camouflage as the Industrial Revolution deposited soot on trees. (I haven't heard whether it is now changing back with controls to fight air pollution!)
However, many species today are observed to be changing their habits, and even their body size, in apparent response to the warming climate we are now observing virtually worldwide. These changes may have very important ecological effects as warming proceeds--for instance, certain insects now hatch earlier than before, and the birds who depend on that hatch are now "out of sync" with their food source. Can they "catch up" in their adaptation? And if not, are they at risk for extinction?
Lastly, the phenomenon of antibiotic resistance is a growing public health problem--more and more of our antibiotic drugs are becoming ineffective as the bugs they are meant to fight develop immunity to their effects with long exposure. That's Darwinian adaptation, too--and it poses a policy problem that humans haven't solved too effectively for the most part. (Partly that's because the routine use of antibiotics in livestock production is just too profitable.)